Preservation of latex



assignments, to United States Rubber Company, New York, N. Y., a corporation of New Jersey r No Drawing. Application August 10, 193 7, Serial No. 158,337

solaims. 01160-820) This invention relates to improvements in. ester and base may be used to preserve freshmethods, of preserving latex and the products latex as it comes from thetre'es for shipment thereof. I to various countries. The combination may also Latex is commonly preserved today with from i v be used to preserve a latexthat has already been .5 to 1.25% ammonia. The ammonia in such latex exported from plantation countries with ja'nfunctions both as the basic material for renderother type of preservative after freeing such" ing the latex alkaline to the proper degree, and latex from its original preservative. Forexalso as a germicidal agent'ior preventing bacterial ample, a latex exported from plantation. coungrowth and the consequent development of acid" trieslwith the usual 1 to 1,25% ammonia can, l0 in the latex which would result in coagulation. if desired, be substantially freed of its ammonia 10 While ammonia is a satisfactory base for proafter arrival at its destination as by blowing air Y ducing the desired alkalinity, it's germicidal prop-- through it and re-preserved with small amounts erties are so. feeble that, if it is .toact'also as the of alkyl mercury ester and base as above degermicidal agent, it must be used in concentrascribedq}. I I r v tions greatly in'excessof those necessary'to other- .The alkyl mercury esters are very'poisonous l6 wise merely'obtain a satisfactory alkalinity. and generally h o d are diluted a: a e, The present invention'relatesto-the preservaamount of inert material such as ammonium or vtion of latexwith smaller amounts of ammonia sodium sulphate; As a rule the materials 'on than generally. used in'latex preservation prothe market contain not more thanB or 4% 1of '20 cedureswhere'ammonia' is the sole preservative. he ac ve ingredient- The material a 0 20,

In carrying out the present invention, latex t'ainedmay. be added to, the latex mixed with is preserved against putrefaction and coagulawater in which the carrier as above'would be tion' by the addition thereto of small amounts solubleerld in Which t y e ury e te i of an alkyl mercuric ester, such as ethyl mereasily dispersed. If the inert carrier for the cury chloride, in combination with ammonia yl e cury ester is insoluble in water, the. 25

or other base. The alkyl mercuric ester .acts Whole may be p sed in water prior to adding as a germicidal agent, and from .01'to ,.lpart it to the latex. Thedesire a ou t of am of the ester per l00 parts of latex is the premonia or othe b e ay, f desired, be added ferred range for preventing bacterial growth, to thesolution or suspension of the alkyl mer a Larger amounts of alkyl mercuric esters, of cury ester. and inert material prior to-its addi- 30 course, may be added but proportions in excess rrtO t e l t'e I of 1% a deemed unnecessary, Whil ethyl Latex as it ,comes from the tree, to which has mercury chloride is the present preferredernbeen d d p ammonia P 9 P r bodiment' ofthe alkyl mercury ester for the latex, will coagulate in 3 days. Portions. of mercial reasons, other esters, .such as ethyl the same latex containing 2% ammonia andto 3'5.

mercury oleate, ethyl'mercury phosphate, ethyl which are'added .01% et y r e-3. mercury sulphate, ethyl mercury nitrate, and and .l%'. et y mercury Chloride, p iv y. i l alkyl-mercury t r it other alkyl will remain-stableforextended periodsof time.

radicals than, the ethyl radical, for xa l Fresh latex to which is added as much as .75 40 methyl,- propyl, isobutyl, may be used, preferp Of ammonia D 100 parts of latex, may 40' ably, as above described, in amountswfrcm .01 to develop a bad odorand have a reduced'stability 1% The, it of 2 to .75 part i within six months. The same latex containing, per 100' parts "latex has been found sufiicient i am r nd P Of ethyl e u y ammonia for proper preservation oflatex in the o d v lops no Of -odor and has a much 5 presence of alkyl mercury esters. Other bases higher Stability than latex Without? the alkyl 45,

' than ammonia, for example, fixed alkalies, such mercury ester in this pe Of t meas sodium and potassium hydroxides, and water- It is thus seen that the use of small amounts solubleorganic derivatives of ammonia, for exa y e y esters in latex p va o ample, basic *aminessuch as the mono-, diand processes permitsa reduction in the'amount' of tri-alkyl amines, preferably in amounts rangammonia over that used where the ammonia is 50 ing from .2 to 5%, maybe used inconjunction the sole preservative. The ammonia may also with the ethyl mercury ester which, as in the be'satisfactorily replaced by other bases which case of its use with ammonia as described above, impart the desired alkalinity to the latex in the is preferably present in amounts ranging from presence of the alkyl mercury ester] I .01 to .1%. The combination of alkyl mercury It is. obvious that various modifications willfl55 suggest. themselves to persons skilled in the art and it is not desired to limit the invention otherwise than as set forth in the appended claims.

Having thus described my invention, what I.

claim and desire to protect by Letters Patient is:

1. Latex containing .01 to .1% of an alkyl mercury ester and a small amount of a base from the group consisting ofammonia, watersoluble' organic derivatives of ammonia, and fixed alkalies.

2. Latex containing .01 to .1% alkyl mercury ester and .2 to 315% ammonia.

' este'rand .2 to .5% of analkali metal hydroxide.

JOHN MOGAVACK. 

